Too Many Pills

A man has been prescribed 10 pills. Starting today, he must take one pill a day, but because the concentration of the medicine is different in each pill, he must take them in a specific order. Since the pills look the same, the man decided to write numbers on each pill to help him remember the order he needs to take them in.

What is the least amount of pills he has to number if he wants to keep track of the order?

Answer

8

Since he has to start the medicine today, the first thing for him to do is take the first pill.
Next, he labels 2-9. He doesn't need to label pill number 10 because it will be the only one without a label.Hide

I said 9. I considered 8, but assumed that he might be taking the first pill later in the day, not necessarily right away. Being categorized a logic puzzle, this should have been made clear. Trick/situation/mystery can have untold significant information, but logic should not.